Biomedical subjects

S A James

Publications and source records attributed to S A James.

At least 19 recordsLinked to original sources

PubMed2003

Identification of yeasts isolated from Nigerian sugar cane peels.

A pilot study was carried out to determine the yeast species associated with sugar cane peels recovered from three separate dumping sites found in Ojo, a typical market town in Nigeria. Species identities were determined by 26S ribosomal DNA (rDNA) sequencing. By using this method, a total of 6 different yeasts were identified, with Candida tropicalis, a recognised human yeast pathogen, being the species most frequently isolated from these dumping sites. The implications of this and other findings of the study, the apparent first of its kind, are discussed in detail.

DNA, Fungal↗

PubMed2002

Identification and distribution of a novel Malassezia species yeast on normal equine skin.

This study aimed to investigate the distribution of Malassezia species yeasts on the skin of healthy horses. Acetate tape samples were obtained from the lip, axilla, interbulbar region, groin and anus of 12 healthy horses. The samples were stained and examined microscopically and sites harbouring yeast-like organisms were identified. Contact plates were applied to the skin at these sites and cultured at 26 degrees C and 32 degrees C. No growth was obtained on horse blood, Sabouraud's dextrose or modified Dixon's agar. A pure growth of a Malassezia-type organism was obtained on Sabouraud's dextrose agar enriched with oleic acid when it was incubated at 30 degrees C. It was identified by 26S ribosomal DNA D1/D2 sequence analysis as a member of the genus Malassezia, and most closely related to Malassezia sympodialis. However, the level of sequence divergence indicated that it was a novel species.

Animals↗

PubMed2002

Nosocomial transmission of Saccharomyces cerevisiae in bone marrow transplant patients.

Saccharomyces cerevisiae is an unusual cause of clinical infection. We describe three bone marrow transplant patients on a haematology unit who developed possible invasive disease with the organism. Two patients died and both these patients appeared to have a related strain of S. cerevisiae. Screening for S. cerevisiae from throat and stool samples revealed four further patients who were carriers. Genotyping of the invasive and carriage strains demonstrated an indistinguishable strain from patients who had been on the unit at the same time, suggesting cross-infection.

Adult↗

PubMed2002

Candida davenportii sp. nov., a potential soft-drinks spoilage yeast isolated from a wasp.

During a survey of yeast ecology in a soft-drinks production facility, a dead wasp was removed from the sampling tap of an external sugar-syrup storage tank. A yeast isolated from the dead wasp was found to be similar, although not identical, in its physiological characteristics to Candida lactis-condensi and Candida stellata. Sequence analysis of the 26S rDNA D1/D2 variable domain revealed that this isolate was most closely related to C stellata, but differed sufficiently in its D1/D2 sequence to indicate that it belonged to a separate species. The yeast species has been named Candida davenportii sp. nov.; the type strain is NCYC 3013T (= CBS 9069T). C davenportii sp. nov. was osmotolerant, moderately preservative-resistant and able to grow in very acidic conditions, i.e. pH 14. This yeast grew well in fruit-containing soft drinks, cola-type beverages and a synthetic soft drink and is therefore a potential cause of spoilage of soft drinks and other sugary food products. Other related yeast species in the same taxonomic clade as C davenportii sp. nov. are also osmotolerant, growing in < 50% (w/v) sugar. Many of these species are associated with insects, specifically bees, bumblebees and leafcutter bees, and many have been reported as the causative agent of spoilage of sugary foods, such as condensed milk, fruit juices and concentrates. It is proposed that C davenportii sp. nov. and other closely related yeasts are primarily associated with Aculeates (bees and wasps). In turn, bees and wasps are attracted by sugary residues in foods such as fruit juices and concentrates, forming the source of infection of these yeasts and thus instigating spoilage.

Animals↗

PubMed2002

Race and glomerulonephritis in patients with and without hepatosplenic Schistosomiasis mansoni.

BACKGROUND/AIMS: United States investigators have shown evidence of higher susceptibility to focal segmental glomerulosclerosis (FSGS) in blacks than in whites. This association between race and FSGS has not been assessed outside the US. The present study assesses the association between race and type of glomerulonephritis in a sample of Brazilian patients, taking into account the presence of the hepatosplenic form of Schistosomiasis mansoni (HSM). METHODS: Eighty patients with focal segmental glomerulosclerosis (FSGS) were compared to 50 with membranoproliferative glomerulonephritis (MPGN). The association between race (i.e. black versus white) and type of glomerulonephritis was adjusted for age, gender and HSM by logistic regression. RESULTS: Blacks were more likely than whites to have FSGS (as compared to MPGN), both among patients with HSM (odds ratio (OR) = 2.67; 95% confidence interval (CI) = 0.81 - 8.81) and without HSM (OR = 2.19; 95% CI = 0.79 - 6.05). After adjustment for age, gender and HSM, the odds of FSGS remained significantly greater for blacks (OR = 2.49; 95% CI = 1.05 - 5.95). CONCLUSION: The increased likelihood of FSGS in Brazilian blacks is consistent with findings from US patients. The association between race and type of glomerulonephritis was similar between patients with and without HSM. Future investigations should focus on the mediators factors that might explain these findings.

Adolescent↗

PubMed2001

Adverse events associated with hepatitis B vaccine in U.S. children less than six years of age, 1993 and 1994.

PURPOSE: This study evaluated infrequent adverse reactions to hepatitis B vaccine by investigating the association of this vaccine with adverse health outcomes for U.S. children less than six years of age. The evaluation of the association between hepatitis B vaccine and chronic arthritis provides needed data, relevant to the Institute of Medicine's Report that there are inadequate data available to assess the causal relationship of hepatitis B vaccine to arthritis risk. METHODS: The 1993 (n = 5505 children) and 1994 (n = 6515 children) National Health Interview Survey (NHIS) datasets were analyzed to provide post-marketing surveillance data from probability samples of the U.S. population. Incident cases of adverse events were determined from the temporal association between the hepatitis B vaccination and the adverse events. Logistic regression modeling was used to adjust for potential confounding. RESULTS: Controlling for age, race, and gender simultaneously in the 1994 NHIS, hepatitis B vaccine was found to be associated with prevalent arthritis [odds ratio (OR) = 5.91, 95% confidence interval (CI) = 1.05-33.14], incident acute ear infections (OR = 1.60, 95% CI = 1.00-2.58), and incident pharyngitis/nasopharyngitis (OR = 1.41, 95% CI = 0.95-2.09). CONCLUSIONS: Evidence from this study suggests that hepatitis B vaccine is positively associated with adverse health outcomes in the general population of US children.

Arthritis↗

PubMed2001

Candida sorbosivorans sp. nov., a new member of the genus Candida Berkhout.

A yeast, strain NCYC 2938T, was isolated from contaminated industrial material. This material was involved in a cascade continuous process for oxidizing sorbitol (D-glucitol) to L-sorbose. The isolate is similar, although not identical, to Candida geochares and Candida magnoliae in its physiological characteristics. Sequence analysis of the 26S rDNA D1/D2 variable domain showed that it was similar to those of both Candida species, but differed sufficiently to be considered as a separate species. Both the physiological characteristics and the unique 26S rDNA D1/D2 sequence of NCYC 2938T are described here, and the yeast has been named Candida sorbosivorans sp. nov. The type strain is NCYC 2938T (= CBS 8768T).

Candida↗

PubMed2001

Phylogenetic analysis of the psychrophobic yeast Arxiozyma telluris and the reinstatement of Candida pintolopesii (van Uden) Meyer et Yarrow and Candida slooffii van Uden et do Carmo Sousa.

A phylogenetic analysis was conducted upon ten strains of the psychrophobic yeast species Arxiozyma telluris using nuclear rDNA (18S and 26S) and mitochondrial cytochrome-c oxidase subunit II (COX2) gene sequences. Strains examined included those described originally as Candida slooffii, Torulopsis bovina (= Candida bovina) and Torulopsis pintolopesii (= Candida pintolopesii), which are all currently accepted as synonyms of Arxiozyma telluris. Comparative 18S rDNA sequence analysis showed that these strains formed a genealogically highly related group, which was phylogenetically distinct from any other ascomycetous species studied. The results showed that A. telluris, as currently described, appears to be composed of a complex of closely related but nevertheless separate taxa. rDNA and COX2 gene sequence data revealed that CBS 1787T, the type strain of C. pintolopesii, the currently recognized asexual form (anamorph) of A. telluris, along with strains CBS 2676 and CBS 2985 formed a distinct taxon that is phylogenetically separate from A. telluris. Similarly, the sequence data also showed that C. slooffii is a distinct taxon and support the reinstatement of this species. However, with regard to the relationship between the type strains of A. telluris (CBS 2685T) and C bovina (CBS 2760T), discrepancies were observed between the rDNA and COX2 sequence datasets, and these results are discussed in more detail.

Candida↗

PubMed2001

Disentangling measures of individual perceptions of community social dynamics: results of a community survey.

This study examined how different measures of individual perceptions of community social dynamics relate to each other and how these measures relate to self-reported general health and depressive symptoms. Results of a principal components analysis conducted to investigate the interrelationships between these individual measures suggest that these measures measure separate phenomena. In addition, in results of multiple-regression analyses conducted to examine associations between the various measures of individual perceptions of community social dynamics and the dependent variables of self-reported general health and depressive symptoms, sense of community, perceived neighborhood control, and neighborhood participation were all associated with the outcome variables in separate regression models. In a regression model with these three variables added to control variables, only sense of community was significantly, albeit modestly, associated with depressive symptoms and self-reported general health.

Adolescent↗

PubMed2000

Sorbic acid resistance: the inoculum effect.

Zygosaccharomyces is a genus associated with the more extreme spoilage yeasts. Zygosaccharomyces spoilage yeasts are osmotolerant, fructophiles (preferring fructose), highly-fermentative and extremely preservative-resistant. Zygosaccharomyces bailii can grow in the presence of commonly-used food preservatives, benzoic, acetic or sorbic acids, at concentrations far higher than are legally permitted or organolepically acceptable in foods. An inoculum effect has been described for many micro-organisms and antimicrobial agents. The minimum inhibitory concentration (MIC) increases with the size of the inoculum; large inocula at high cell density therefore require considerably higher concentrations of inhibitors to prevent growth than do dilute cell suspensions. A substantial inoculum effect was found using sorbic acid against the spoilage yeast Zygosaccharomyces bailii NCYC 1766. The inoculum effect was not caused by yeasts metabolizing or adsorbing sorbic acid, thereby lowering the effective concentration; was not due to absence of cell-cell signals in dilute cell suspensions; and was not an artefact, generated by insufficient time for small inocula to grow. The inoculum effect appeared to be caused by diversity in the populations of yeast cells, with higher probability of sorbic acid-resistant cells being present in large inocula. It was found that individual cells of Zygosaccharomyces bailii populations, grown as single cells in microtitre plate wells, were very diverse, varying enormously in resistance to sorbic acid. 26S ribosomal DNA sequencing did not detect differences between the small fraction of resistant 'super cells' and the average population. Re-inoculation of the 'super cells' after overnight growth on YEPD showed a normal distribution of resistance to sorbic acid, similar to that of the original population. The resistance phenotype was therefore not heritable and not caused by a genetically distinct subpopulation. It was concluded that resistance of the spoilage yeast Zygosaccharomyces bailii to sorbic acid was due to the presence of small numbers of phenotypically resistant cells in the population.

Base Sequence↗

PubMed2000

Chromosomal evolution in Saccharomyces.

The chromosomal speciation model invokes chromosomal rearrangements as the primary cause of reproductive isolation. In a heterozygous carrier, chromosomes bearing reciprocal translocations mis-segregate at meiosis, resulting in reduced fertility or complete sterility. Thus, chromosomal rearrangements act as a post-zygotic isolating mechanism. Reproductive isolation in yeast is due to post-zygotic barriers, as many species mate successfully but the hybrids are sterile. Reciprocal translocations are thought to be the main form of large-scale rearrangement since the hypothesized duplication of the whole yeast genome 10(8) years ago. To test the chromosomal speciation model in yeast, we have characterized chromosomal translocations among the genomes of six closely related species in the Saccharomyces 'sensu stricto' complex. Here we show that rearrangements have occurred between closely related species, whereas more distant ones have colinear genomes. Thus, chromosomal rearrangements are not a prerequisite for speciation in yeast and the rate of formation of translocations is not constant. These rearrangements appear to result from ectopic recombination between Ty elements or other repeated sequences.

Chromosomes, Fungal↗

PubMed2000

Acculturation and blood pressure in a community-based sample of Chaldean-American women.

With the steady increase of non-European, non-English speaking immigrants to the United States, the relationship between acculturation and risk for cardiovascular disease (CVD) is an issue of growing importance to researchers interested in the health of new immigrant populations. The influence of acculturation processes on adverse changes in blood pressure (BP), a major risk factor for CVD, has been examined in Hispanic-Americans and Asian-Americans. Published studies on this relationship in Arab-Americans are lacking, however, despite their growing numbers. With a specific focus on Chaldean-Americans, a major subgroup of the large Arab-American population located in metropolitan Detroit, Michigan, the current study investigates the influence of level of acculturation on BP in a community probability sample of 130 Chaldean-American women. Study participants were interviewed in their homes (92% response rate). Physical measurements included BP, body mass index (BMI), and waist-hip ratio. Demographic and acculturation data were obtained through a standardized questionnaire. The crude hypertension prevalence in the sample was 16%. Three dimensions of acculturation were identified through content and factor analysis: English language preference, parental school involvement, and ethnic identity. In unadjusted analyses, both English language preference and Chaldean-American ethnic identity were associated (p < 0.01) with lower mean BP, but these differences became nonsignificant when age, BMI, and waist-hip ratio were statistically controlled. Parental school involvement was not associated with BP in any analyses. In this study, the strongest predictors of BP were BMI and waist-hip ratio, both of which were inversely correlated with age, education, English language preference, employment outside the home, and parental school involvement. Future studies of acculturation and BP in Chaldean-Americans (and other Arab-American populations) should use improved measures of acculturation, broader assessments of behavioral and socioeconomic status, and larger samples that includes both genders.

Journal Article↗

PubMed2000

Unintended pregnancy and preterm birth.

About one-third of all pregnancies that result in live births in the US are unintended. Despite the large number of these births, little is known about the outcomes of unintended pregnancies. The purpose of the current study was to evaluate the association between intendedness of pregnancy and preterm birth in a large prospective cohort of women who reported for prenatal care. Pregnant, black, low-income women were enrolled into this study at four hospital-based prenatal care clinics and one off-site hospital-affiliated prenatal clinic in Baltimore City. A self-administered questionnaire to assess demographic and psychosocial data was completed by each woman in the cohort at the time of enrolment in the study. The questionnaire contained an item to measure intendedness of the pregnancy. A total of 922 women comprised the final sample for analysis. For the analyses, intendedness was dichotomised as: intended (wanted now or sooner) vs. unintended (mistimed, unwanted or unsure). Overall, 13.7% of all births to women in the sample were preterm. In a logistic regression model, after controlling for potential confounding by clinical and behavioural predictors of preterm delivery, unintended pregnancy was significantly associated with preterm delivery (adjusted RR = 1.82, 95% confidence interval [1.08,3.08], P = 0.026). In this study of a cohort of urban, clinic-attending, low-income, pregnant black women, unintended pregnancy had a statistically significant association with preterm birth. After adjustment for behavioural and clinical risks, women with unintended pregnancies had almost twice the risk of a preterm delivery as women with intended pregnancies.

Adolescent↗

PubMed2000

Influence of light availability on leaf structure and growth of two Eucalyptus globulus ssp. globulus provenances.

Light availability strongly affects leaf structure of the distinctive ontogenetic leaf forms of Eucalyptus globulus Labill. ssp. globulus. Late-maturing plants from St. Marys, Tasmania and early maturing plants from Wilsons Promontory, Victoria (hereafter referred to as Wilsons Prom.) were grown for 9 months in 100, 50 or 10% sunlight. Growth, biomass and leaf area were significantly reduced when plants were grown in 10% sunlight. Provenance differences were minimal despite retention of the juvenile leaf form by the Tasmanian plants throughout the study. The time taken for initiation of vegetative phase change by the Wilsons Prom. saplings increased with decreasing light availability, but the nodal position of change on the main stem remained the same. Both juvenile and adult leaves remained horizontal in low light conditions, but became vertical with high irradiance. Leaf dimensions changed with ontogenetic development, but were unaffected by light availability. Juvenile leaves retained a dorsiventral anatomy and adult Wilsons Prom. leaves retained an isobilateral structure despite a tenfold difference in light availability. Stomatal density and distribution showed ontogenetic and treatment differences. At all irradiances, juvenile leaves produced the smallest stomata and adult leaves the largest stomata. Amphistomy decreased with decreasing irradiance. Detrended, correspondence analysis ordination highlighted the structural changes influenced by ontogenetic development and light availability. Adult leaves had characteristics similar to the xeromorphic, sun-leaf type found in arid, high-light conditions. Although juvenile leaves had characteristics typical of mesomorphic leaves, several structural features suggest that these leaves are more sun-adapted than adult leaves.

Eucalyptus↗

PubMed2000

Three new species in the Saccharomyces sensu stricto complex: Saccharomyces cariocanus, Saccharomyces kudriavzevii and Saccharomyces mikatae.

On the basis of genetic analysis, molecular karyotyping and sequence analyses of the 18S rRNA and internal transcribed spacer (ITS) region, three new Saccharomyces species are described, Saccharomyces cariocanus (with type strain NCYC 2890T), Saccharomyces kudriavzevii (with type strain NCYC 2889T) and Saccharomyces mikatae (with type strain NCYC 2888T). Genetic and molecular analyses did not confirm the previously observed conspecificity of Saccharomyces paradoxus and S. cariocanus. The latter species exhibits postzygotic isolation from representative strains from all known geographical populations of S. paradoxus: European, Far-East Asian, North American and Hawaiian.

DNA, Fungal↗

PubMed2000

Unfair treatment, neighborhood effects, and mental health in the Detroit metropolitan area.

Why do racial differences in many indicators of mental and emotional well-being show inconsistent patterns? We propose that mental and emotional well-being are influenced by aspects of the social context, including experiences of unfair treatment and the concentration of households with incomes below the poverty level, and that differential exposure to these factors influences racial differences in mental well-being. We analyze the reporting of psychological distress and life satisfaction in a multistage area probability sample of 1,139 African American and white residents of the Detroit metropolitan area aged 18 and older. Both psychological distress and life satisfaction are significantly associated with exposure to unfair treatment and with the proportion of households in the census block group that were below the poverty level. Racial differences in psychological distress and life satisfaction were eliminated or reversed once differentials in the percent of households living below the poverty line and exposure to unfair treatment were accounted for. These findings contribute to a growing body of evidence that "race" effects operate through multiple pathways that include race-based residential segregation and its attendant economic disinvestment at the community level, and interpersonal experiences of unfair treatment.

Adolescent↗

PubMed2000

Race, clinical factors and pre-term birth in a low-income urban setting.

UNLABELLED: While infant mortality rates have declined for both White and African-American populations, the perennial two-fold excess in risk for African Americans remains unchanged, and indeed, may have increased since 1985. One potential explanation for the excess risk in African Americans might be racial differences in maternal clinical risk factors, such as prior pregnancy history and pregnancy complications. This paper examines the contributions of such clinical indicators to racial differences in pre-term delivery in a study sample of urban, low-income women, aged 18 to 43 years. METHODS: Study participants were enrolled during their first prenatal care visit at one of four hospital-based, prenatal care clinics in Baltimore City. Medical history and pregnancy outcome data were abstracted from clinical records. Multiple logistic regression models were used to assess the independent relationship between race and pre-term birth, after controlling for clinical factors. RESULTS: Without adjustment for clinical risk factors, African-American women were 1.8 times more likely than White women to have a pre-term birth outcome (95% confidence interval 1.20-2.78). After statistical adjustment for the clinical variables, however, the association between race and pre-term birth was diminished (OR = 1.64, 95% confidence interval: 0.99-2.72). Moreover, the associations between certain clinical risks and pre-term birth were stronger for African-American than White women. CONCLUSION: These results suggest that attention to clinical risk factors among African-American women may be an important avenue for reducing Black/White racial disparities in pre-term birth.

Adolescent↗

PubMed1999

Primordial prevention of cardiovascular disease among African-Americans: a social epidemiological perspective.

BACKGROUND: The primordial prevention of cardiovascular disease (CVD) among African-Americans represents a formidable challenge for public health. This paper discusses the nature of this challenge, highlighting the role that economic and cultural factors play in shaping the distributions of major CVD risk factors among African-Americans. The paper concludes with specific suggestions for research. METHODS: Data from recent national health surveys on black/white differences in major CVD risk factors like hypertension, obesity, cholesterol, cigarette smoking, and physical inactivity were reviewed for the purpose of identifying promising avenues for primordial prevention research among African-Americans. RESULTS: Cigarette smoking has a delayed onset among African-Americans compared to whites. Black/white differences in "vigorous" leisure-time physical activity (e.g., social dancing and team sports) are not apparent until around age 40. These findings have relevance for primordial prevention work in black communities since they suggest the existence of broad-based, health-relevant cultural norms which could support primordial prevention programs, such as regular physical activity, across the life cycle. CONCLUSIONS: CVD primordial prevention programs among African-Americans must be grounded in an understanding of how cultural values as well as economic conditions shape CVD risk factor distributions in this population. Ultimate success will depend on the strength of the partnerships that public health researchers, primary care providers, and community residents are able to build.

Black or African American↗